Change the CI test running command

We have realized in the https://github.com/RedHatInsights/sources-api-go/pull/193 pull request that even though that CI says that the tests pass, it seems that it is not running all the tests from the suite, thus rendering the CI tests unreliable.

We need to change the command so that it includes all the tests. Right now the issued command in CI is:

go test --integration ./...

What it seems to execute everything is the following command:

go test ./... -integration